/* EST Math Quiz — Frontend Styles */
/* Uses CSS variables injected per-instance via data attributes */

.est-quiz-root {
  --est-primary: #d4a843;
  --est-primary-dim: rgba(212, 168, 67, 0.15);
  --est-primary-dark: #b8832a;
  --est-bg: #06080f;
  --est-bg2: #0c1018;
  --est-surface: #111620;
  --est-surface2: #181f2e;
  --est-border: #252d42;
  --est-border2: #2e3a52;
  --est-text: #e2e8f4;
  --est-text2: #94a3b8;
  --est-text3: #4a5568;
  --est-blue: #3b82f6;
  --est-blue-dim: rgba(59, 130, 246, 0.12);
  --est-green: #22c55e;
  --est-green-dim: rgba(34, 197, 94, 0.12);
  --est-red: #ef4444;
  --est-red-dim: rgba(239, 68, 68, 0.12);
  --est-amber: #f59e0b;
  --est-radius: 14px;
  --est-radius-sm: 8px;

  background: var(--est-bg);
  color: var(--est-text);
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  border-radius: 20px;
  padding: 32px;
  max-width: 860px;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
  line-height: 1.6;
}

.est-quiz-root::before {
  content: '';
  position: absolute; inset: 0; z-index: 0; pointer-events: none;
  background:
    radial-gradient(ellipse 80% 50% at 15% -10%, rgba(212,168,67,0.07) 0%, transparent 55%),
    radial-gradient(ellipse 60% 60% at 85% 110%, rgba(59,130,246,0.05) 0%, transparent 55%);
}

.est-quiz-root * { box-sizing: border-box; margin: 0; padding: 0; }
.est-quiz-root > * { position: relative; z-index: 1; }

/* ── NOTICE ── */
.est-notice { padding: 16px 20px; border-radius: var(--est-radius-sm); font-size: 14px; }
.est-notice-error { background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.3); color: #fca5a5; }

/* ── SCREENS ── */
.est-screen { display: none; }
.est-screen--active { display: block; }
.est-screen--loading { display: none; flex-direction: column; align-items: center; justify-content: center; text-align: center; padding: 60px 20px; min-height: 400px; }
.est-screen--loading.est-screen--active { display: flex; }

/* ── HERO ── */
.est-hero { text-align: center; margin-bottom: 40px; padding-top: 8px; }
.est-hero__eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--est-primary-dim); border: 1px solid rgba(212,168,67,0.3);
  color: var(--est-primary); font-size: 11px; font-weight: 700;
  letter-spacing: 1.5px; text-transform: uppercase;
  padding: 6px 16px; border-radius: 20px; margin-bottom: 20px;
}
.est-hero__title {
  font-size: clamp(32px, 5vw, 52px); font-weight: 800; line-height: 1.05;
  margin-bottom: 14px; color: var(--est-text);
}
.est-hero__highlight {
  background: linear-gradient(135deg, var(--est-text) 30%, var(--est-primary) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.est-hero__sub { color: var(--est-text2); font-size: 15px; max-width: 460px; margin: 0 auto; }

/* ── CARDS ── */
.est-card {
  background: var(--est-surface); border: 1px solid var(--est-border);
  border-radius: 18px; padding: 24px; margin-bottom: 18px;
  position: relative; overflow: hidden; transition: border-color .2s;
}
.est-card::before {
  content: ''; position: absolute; top: 0; left: 0;
  width: 3px; height: 100%;
  background: linear-gradient(180deg, var(--est-primary), transparent);
}
.est-card:hover { border-color: var(--est-border2); }
.est-card__head { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.est-card__icon { font-size: 20px; }
.est-card__title { font-size: 15px; font-weight: 700; }
.est-card__sub { font-size: 12px; color: var(--est-text2); }

/* ── TOPIC GRID ── */
.est-topic-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 8px;
}
.est-topic-item {
  display: flex; align-items: center; gap: 10px;
  background: var(--est-bg2); border: 1px solid var(--est-border);
  border-radius: var(--est-radius-sm); padding: 10px 14px;
  cursor: pointer; transition: all .15s;
}
.est-topic-item:hover { border-color: var(--est-border2); }
.est-topic-item--checked { border-color: rgba(59,130,246,0.5); background: var(--est-blue-dim); }
.est-topic-cb {
  width: 18px; height: 18px; border: 2px solid var(--est-border2);
  border-radius: 4px; flex-shrink: 0; position: relative; transition: all .15s;
}
.est-topic-item--checked .est-topic-cb { background: var(--est-blue); border-color: var(--est-blue); }
.est-topic-item--checked .est-topic-cb::after {
  content: '✓'; position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; font-weight: 800; color: #fff;
}
.est-topic-name { font-size: 13px; font-weight: 500; }

/* ── DIFFICULTY ── */
.est-diff-row { display: flex; gap: 10px; flex-wrap: wrap; }
.est-diff-btn {
  flex: 1; min-width: 120px; padding: 12px 16px;
  background: var(--est-bg2); border: 1.5px solid var(--est-border);
  border-radius: var(--est-radius-sm); cursor: pointer; font-size: 14px; font-weight: 600;
  color: var(--est-text2); transition: all .18s; position: relative;
  font-family: inherit;
}
.est-diff-btn:hover { border-color: var(--est-border2); color: var(--est-text); }
.est-diff-btn--on {
  border-color: var(--est-primary); background: var(--est-primary-dim); color: var(--est-text);
}
.est-diff-check {
  display: none; position: absolute; top: 8px; right: 8px;
  width: 18px; height: 18px; background: var(--est-primary); color: #000;
  border-radius: 50%; font-size: 10px; font-weight: 800;
  align-items: center; justify-content: center;
}
.est-diff-btn--on .est-diff-check { display: flex; }

/* ── SESSION SETTINGS ── */
.est-settings-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.est-settings-label {
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: .8px; color: var(--est-text2); margin-bottom: 10px;
}
.est-q-opts { display: flex; gap: 8px; flex-wrap: wrap; }
.est-q-btn {
  padding: 9px 16px; background: var(--est-bg2); border: 1.5px solid var(--est-border);
  border-radius: var(--est-radius-sm); color: var(--est-text2); font-size: 13px; font-weight: 600;
  cursor: pointer; transition: all .15s; font-family: inherit;
}
.est-q-btn:hover { border-color: var(--est-border2); color: var(--est-text); }
.est-q-btn--on { border-color: var(--est-primary); background: var(--est-primary-dim); color: var(--est-text); }

/* MODEL SELECT */
.est-model-wrap { position: relative; }
.est-model-select {
  width: 100%; background: var(--est-bg2); border: 1px solid var(--est-border);
  border-radius: var(--est-radius-sm); color: var(--est-text);
  padding: 11px 36px 11px 14px; font-size: 14px; font-family: inherit;
  appearance: none; cursor: pointer; outline: none; transition: border-color .2s;
}
.est-model-select:focus { border-color: var(--est-primary); }
.est-model-wrap::after {
  content: '▾'; position: absolute; right: 13px; top: 50%;
  transform: translateY(-50%); color: var(--est-text2); pointer-events: none;
}

/* START BUTTON */
.est-start-btn {
  width: 100%; margin-top: 24px;
  background: linear-gradient(135deg, var(--est-primary) 0%, var(--est-primary-dark) 100%);
  border: none; border-radius: var(--est-radius); color: #000;
  font-size: 17px; font-weight: 700; padding: 18px;
  cursor: pointer; position: relative; overflow: hidden;
  transition: transform .15s, box-shadow .15s; font-family: inherit;
  box-shadow: 0 4px 24px rgba(212,168,67,0.3);
}
.est-start-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(212,168,67,0.45); }
.est-start-btn:active { transform: translateY(0); }
.est-start-btn:disabled { opacity: .45; cursor: default; transform: none; box-shadow: none; }
.est-back-btn {
  flex: 1; max-width: 200px; padding: 14px 20px;
  background: var(--est-surface); border: 1px solid var(--est-border);
  color: var(--est-text); border-radius: var(--est-radius-sm);
  font-size: 14px; font-weight: 600; cursor: pointer;
  transition: all .15s; font-family: inherit;
}
.est-back-btn:hover { border-color: var(--est-border2); background: var(--est-surface2); }

/* ERROR BOX */
.est-error-box {
  background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.3);
  border-radius: var(--est-radius-sm); padding: 14px 18px;
  font-size: 13px; color: #fca5a5; margin-top: 12px; display: none;
}
.est-error-box.est-visible { display: block; }

/* ── LOADING ── */
.est-loading-orb {
  width: 80px; height: 80px; margin-bottom: 32px; border-radius: 50%;
  background: var(--est-primary-dim); border: 2px solid rgba(212,168,67,0.3);
  position: relative; animation: estOrbPulse 2s ease infinite;
}
.est-loading-orb::before, .est-loading-orb::after {
  content: ''; position: absolute; border-radius: 50%;
  border: 2px solid transparent; animation: estOrbSpin 1.8s linear infinite;
}
.est-loading-orb::before { inset: 6px; border-top-color: var(--est-primary); }
.est-loading-orb::after { inset: 14px; border-bottom-color: rgba(212,168,67,0.5); animation-duration: 1.2s; animation-direction: reverse; }
.est-loading-math { font-size: 26px; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%); color: var(--est-primary); }
@keyframes estOrbPulse { 0%,100%{box-shadow:0 0 20px rgba(212,168,67,0.2)} 50%{box-shadow:0 0 40px rgba(212,168,67,0.4)} }
@keyframes estOrbSpin { to { transform: rotate(360deg); } }
.est-loading-title { font-size: 24px; font-weight: 800; margin-bottom: 8px; }
.est-loading-sub { color: var(--est-text2); font-size: 14px; max-width: 360px; }
.est-loading-steps { margin-top: 28px; display: flex; flex-direction: column; gap: 10px; width: 100%; max-width: 340px; }
.est-load-step {
  display: flex; align-items: center; gap: 12px;
  background: var(--est-surface); border: 1px solid var(--est-border);
  border-radius: var(--est-radius-sm); padding: 12px 16px;
  font-size: 13px; color: var(--est-text2);
  opacity: 0; transform: translateX(-10px); transition: all .4s ease;
}
.est-load-step--done { opacity: 1; transform: none; border-color: rgba(34,197,94,0.3); background: var(--est-green-dim); color: var(--est-text); }
.est-load-step--active { opacity: 1; transform: none; border-color: rgba(212,168,67,0.3); }
.est-load-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--est-border2); flex-shrink: 0; transition: background .3s; }
.est-load-step--done .est-load-dot { background: var(--est-green); }
.est-load-step--active .est-load-dot { background: var(--est-primary); animation: estDotPulse .8s ease infinite; }
@keyframes estDotPulse { 0%,100%{transform:scale(1)} 50%{transform:scale(1.6)} }

/* ── QUESTION SCREEN ── */
.est-q-header { margin-bottom: 18px; }
.est-tracker { display: flex; flex-wrap: wrap; gap: 6px; background: var(--est-surface); border: 1px solid var(--est-border); border-radius: var(--est-radius); padding: 14px; margin-bottom: 12px; }
.est-dot {
  width: 30px; height: 30px; border-radius: 7px;
  background: var(--est-bg2); border: 1px solid var(--est-border);
  display: flex; align-items: center; justify-content: center;
  font-size: 10px; font-weight: 700; color: var(--est-text3);
  cursor: pointer; transition: all .15s;
  font-family: 'Courier New', monospace;
}
.est-dot:hover { border-color: var(--est-border2); color: var(--est-text2); }
.est-dot--current { border-color: var(--est-primary); color: var(--est-primary); background: var(--est-primary-dim); }
.est-dot--correct { background: var(--est-green-dim); border-color: rgba(34,197,94,0.4); color: var(--est-green); }
.est-dot--wrong { background: var(--est-red-dim); border-color: rgba(239,68,68,0.4); color: var(--est-red); }

.est-progress-row { display: flex; align-items: center; gap: 12px; }
.est-prog-text { font-size: 12px; color: var(--est-text2); font-family: monospace; min-width: 36px; }
.est-prog-bar { flex: 1; height: 4px; background: var(--est-border); border-radius: 2px; overflow: hidden; }
.est-prog-fill { height: 100%; background: var(--est-primary); border-radius: 2px; transition: width .4s ease; width: 0%; }
.est-timer { display: flex; align-items: center; gap: 6px; background: var(--est-surface); border: 1px solid var(--est-border); padding: 6px 12px; border-radius: var(--est-radius-sm); }
.est-timer-val { font-family: monospace; font-weight: 700; font-size: 16px; color: var(--est-primary); letter-spacing: 2px; min-width: 55px; }
.est-timer-val--warn { color: var(--est-red); animation: estTimerPulse 1s ease infinite; }
@keyframes estTimerPulse { 0%,100%{opacity:1} 50%{opacity:.4} }

/* QUESTION CARD */
.est-q-card {
  background: var(--est-surface); border: 1px solid var(--est-border);
  border-radius: 18px; padding: 30px; margin-bottom: 16px;
  position: relative; overflow: hidden; animation: estCardIn .3s ease;
}
.est-q-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--est-primary), var(--est-blue), transparent);
}
@keyframes estCardIn { from{opacity:0;transform:translateY(14px)} to{opacity:1;transform:translateY(0)} }

.est-q-meta { display: flex; align-items: center; gap: 8px; margin-bottom: 18px; flex-wrap: wrap; }
.est-badge { font-size: 10px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; padding: 4px 10px; border-radius: 5px; }
.est-badge--avg { background: rgba(59,130,246,0.15); color: #60a5fa; border: 1px solid rgba(59,130,246,0.3); }
.est-badge--hard { background: rgba(245,158,11,0.15); color: var(--est-amber); border: 1px solid rgba(245,158,11,0.3); }
.est-badge--super { background: rgba(239,68,68,0.15); color: #f87171; border: 1px solid rgba(239,68,68,0.3); }
.est-topic-tag { font-size: 12px; color: var(--est-text2); background: var(--est-surface2); border: 1px solid var(--est-border); padding: 4px 10px; border-radius: 5px; }
.est-q-num { font-family: monospace; font-size: 12px; color: var(--est-text3); margin-left: auto; }

.est-q-context { background: var(--est-surface2); border-left: 3px solid var(--est-primary); border-radius: 0 var(--est-radius-sm) var(--est-radius-sm) 0; padding: 12px 16px; margin-bottom: 16px; font-size: 14px; color: var(--est-text2); line-height: 1.7; }
.est-q-stem { font-size: 17px; font-weight: 400; line-height: 1.8; color: var(--est-text); }

.est-choices { display: flex; flex-direction: column; gap: 10px; margin-top: 22px; }
.est-choice {
  display: flex; align-items: flex-start; gap: 14px;
  background: var(--est-bg2); border: 1.5px solid var(--est-border);
  border-radius: var(--est-radius-sm); padding: 14px 18px;
  cursor: pointer; text-align: left; transition: all .18s;
  font-size: 15px; line-height: 1.5; color: var(--est-text);
  width: 100%; font-family: inherit;
}
.est-choice:hover:not(:disabled) { border-color: var(--est-border2); background: var(--est-surface2); transform: translateX(3px); }
.est-choice:disabled { cursor: default; }
.est-choice-key {
  font-family: monospace; font-size: 12px; font-weight: 700;
  width: 26px; height: 26px; flex-shrink: 0;
  background: var(--est-surface2); border: 1px solid var(--est-border);
  border-radius: 6px; display: flex; align-items: center; justify-content: center;
  color: var(--est-text2); margin-top: 1px; transition: all .18s;
}
.est-choice--selected { border-color: var(--est-blue); background: var(--est-blue-dim); }
.est-choice--selected .est-choice-key { background: var(--est-blue); color: #fff; border-color: var(--est-blue); }
.est-choice--correct { border-color: var(--est-green); background: var(--est-green-dim); }
.est-choice--correct .est-choice-key { background: var(--est-green); color: #fff; border-color: var(--est-green); }
.est-choice--wrong { border-color: var(--est-red); background: var(--est-red-dim); }
.est-choice--wrong .est-choice-key { background: var(--est-red); color: #fff; border-color: var(--est-red); }

/* EXPLANATION */
.est-explanation { margin-top: 18px; background: var(--est-surface2); border: 1px solid var(--est-border); border-radius: var(--est-radius); padding: 20px; animation: estFadeIn .3s ease; display: none; }
.est-explanation.est-visible { display: block; }
@keyframes estFadeIn { from{opacity:0;transform:translateY(8px)} to{opacity:1;transform:translateY(0)} }
.est-exp-head { display: flex; align-items: center; gap: 8px; margin-bottom: 12px; font-weight: 700; font-size: 14px; }
.est-exp-correct { color: var(--est-green); }
.est-exp-wrong { color: var(--est-red); }
.est-exp-body { font-size: 14px; color: var(--est-text2); line-height: 1.85; }
.est-exp-formula { background: var(--est-bg); border: 1px solid var(--est-border); border-radius: var(--est-radius-sm); padding: 12px 16px; margin-top: 12px; font-family: monospace; font-size: 13px; color: var(--est-primary); }

/* Q NAV */
.est-q-nav { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; }
.est-nav-btn {
  display: flex; align-items: center; gap: 8px;
  background: var(--est-surface); border: 1px solid var(--est-border);
  color: var(--est-text); border-radius: var(--est-radius-sm); padding: 11px 18px;
  font-size: 14px; font-weight: 600; cursor: pointer; transition: all .18s; font-family: inherit;
}
.est-nav-btn:hover:not(:disabled) { border-color: var(--est-border2); background: var(--est-surface2); }
.est-nav-btn:disabled { opacity: .35; cursor: default; }
.est-submit-btn {
  background: linear-gradient(135deg, var(--est-primary), var(--est-primary-dark));
  border: none; color: #000; padding: 11px 24px;
  border-radius: var(--est-radius-sm); font-size: 14px; font-weight: 700;
  cursor: pointer; transition: all .15s; font-family: inherit;
  box-shadow: 0 2px 12px rgba(212,168,67,0.3);
}
.est-submit-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 20px rgba(212,168,67,0.45); }

/* ── RESULTS ── */
.est-results-hero { text-align: center; margin-bottom: 36px; }
.est-score-ring { width: 150px; height: 150px; margin: 0 auto 24px; position: relative; }
.est-score-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.est-ring-bg { fill: none; stroke: var(--est-border); stroke-width: 8; }
.est-ring-fill { fill: none; stroke-width: 8; stroke-linecap: round; transition: stroke-dashoffset 1.5s cubic-bezier(0.4,0,0.2,1); }
.est-score-center { position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; }
.est-score-pct { font-size: 34px; font-weight: 800; line-height: 1; }
.est-score-lbl { font-size: 10px; color: var(--est-text2); text-transform: uppercase; letter-spacing: 1px; margin-top: 4px; }
.est-results-title { font-size: 26px; font-weight: 800; margin-bottom: 6px; }
.est-results-sub { color: var(--est-text2); font-size: 14px; }

.est-stats-row { display: grid; grid-template-columns: repeat(4,1fr); gap: 12px; margin-bottom: 32px; }
.est-stat-card { background: var(--est-surface); border: 1px solid var(--est-border); border-radius: var(--est-radius); padding: 18px 14px; text-align: center; }
.est-stat-val { font-size: 30px; font-weight: 800; margin-bottom: 4px; }
.est-stat-lbl { font-size: 10px; color: var(--est-text2); text-transform: uppercase; letter-spacing: .8px; }

.est-review-title { font-size: 20px; font-weight: 800; margin-bottom: 16px; }
.est-review-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 32px; }
.est-review-item { background: var(--est-surface); border: 1px solid var(--est-border); border-radius: var(--est-radius); overflow: hidden; }
.est-review-head { display: flex; align-items: flex-start; gap: 12px; padding: 14px 18px; cursor: pointer; }
.est-review-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; margin-top: 4px; }
.est-review-q { font-size: 13px; flex: 1; color: var(--est-text2); line-height: 1.5; }
.est-review-chevron { font-size: 12px; color: var(--est-text3); transition: transform .2s; flex-shrink: 0; margin-top: 3px; }
.est-review-item--open .est-review-chevron { transform: rotate(180deg); }
.est-review-body { display: none; padding: 0 18px 18px; border-top: 1px solid var(--est-border); }
.est-review-item--open .est-review-body { display: block; padding-top: 14px; }
.est-review-ans { font-size: 13px; margin-bottom: 10px; }
.est-review-ans span { font-weight: 700; }
.est-review-exp { font-size: 13px; color: var(--est-text2); line-height: 1.8; }

.est-results-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* Responsive */
@media(max-width:600px) {
  .est-quiz-root { padding: 20px 16px; }
  .est-q-card { padding: 18px 16px; }
  .est-q-stem { font-size: 15px; }
  .est-choice { font-size: 14px; padding: 12px 14px; }
  .est-settings-row { grid-template-columns: 1fr; }
  .est-stats-row { grid-template-columns: 1fr 1fr; }
  .est-diff-row { flex-direction: column; }
  .est-topic-grid { grid-template-columns: 1fr; }
}